SQL server:计算SQL查询中的序列

Question

我在SQL Server 2008R2中有以下四个表:

DECLARE @ParentGroup TABLE (ParentGroup_ID INT, ParentGroup_Name VARCHAR(100));
DECLARE @ChildGroup TABLE (ChildGroup_id INT, ChildGroup_name VARCHAR(100), ParentGroup_id INT);
DECLARE @Entity TABLE ([Entity_id] INT, [Entity_name] VARCHAR(100));
DECLARE @ChildGroupEntity TABLE (ChildGroupEntity_id INT, ChildGroup_id INT, [Entity_ID] INT);
INSERT INTO @parentGroup VALUES (1, 'England'), (2, 'USA');
INSERT INTO @ChildGroup VALUES (10, 'Sussex', 1), (11, 'Essex', 1), (12, 'Middlesex', 1);
INSERT INTO @entity VALUES (100, 'Entity0'),(101, 'Entity1'),(102, 'Entity2'),(103, 'Entity3'),(104, 'Entity4'),(105, 'Entity5'),(106, 'Entity6');
INSERT INTO @ChildGroupEntity VALUES (1000, 10, 100), (1001, 10, 101), (1002, 10, 102), (1003, 11, 103), (1004, 11, 104), (1005, 12, 100), (1006, 12, 105), (1007, 12, 106);
/*
SELECT * FROM @parentGroup
SELECT * FROM @ChildGroup
SELECT * FROm @entity
SELECT * FROM @ChildGroupEntity
*/

表格之间的关系如下:

SELECT ParentGroup_Name, ChildGroup_name, [Entity_name],  0 [ChildGroupSequence], 0 [EntitySequence]
FROM @ChildGroupEntity cge
INNER JOIN @ChildGroup cg ON cg.ChildGroup_id=cge.ChildGroup_id
INNER JOIN @parentGroup pg ON pg.parentGroup_id=cg.parentGroup_id
INNER JOIN @entity e ON e.[entity_id]=cge.[Entity_ID]
ORDER BY ParentGroup_Name, ChildGroup_name, [Entity_name]

上述查询的输出是:

-------------------------------------------------------------------------------
ParentGroup_Name|ChildGroup_name|Entity_name|ChildGroupSequence|EntitySequence|
-------------------------------------------------------------------------------
England         |Essex          |Entity3    |0                 |0             |
England         |Essex          |Entity4    |0                 |0             |
England         |Middlesex      |Entity0    |0                 |0             |
England         |Middlesex      |Entity5    |0                 |0             |
England         |Middlesex      |Entity6    |0                 |0             |
England         |Sussex         |Entity0    |0                 |0             |
England         |Sussex         |Entity1    |0                 |0             |
England         |Sussex         |Entity2    |0                 |0             |
-------------------------------------------------------------------------------

现在,我想找出子组和与父组1的子组关联的所有实体.另外,我想计算[ChildGroupSequence],[EntitySequence],如下面的逻辑:

1. ChildGroupSequence列应表示子组在父组中的序列,从1000开始并递增100.即,第一个子组将为1000,第二个子组将为1100.
2. EntitySequence列应表示子组内的实体序列,从100开始并按单个位递增,为每个子组重置.即,子组1中的第一个实体从100开始,子组2中的第一个实体也是如此.

因此,输出应采用以下格式:

-------------------------------------------------------------------------------
ParentGroup_Name|ChildGroup_name|Entity_name|ChildGroupSequence|EntitySequence|
-------------------------------------------------------------------------------
England         |Essex          |Entity3    |1000              |100           |
England         |Essex          |Entity4    |1000              |101           |
England         |Middlesex      |Entity0    |1100              |100           |
England         |Middlesex      |Entity5    |1100              |101           |
England         |Middlesex      |Entity6    |1100              |102           |
England         |Sussex         |Entity0    |1200              |100           |
England         |Sussex         |Entity1    |1200              |101           |
England         |Sussex         |Entity2    |1200              |102           |
-------------------------------------------------------------------------------

我可以通过在应用程序层(.Net程序)中读取值来轻松完成这项工作,但希望通过尝试这样的一些小事来学习SQL服务器.任何人都可以帮我写这个SQL查询吗？

任何帮助将非常感激.提前致谢.

编辑:我的样本数据似乎并没有正确反映第一个规则,该规则规定ChildGroupSequence应该由100递增和1采样输出增加第二个查询反映100 @jpw增量:非常感谢你指出这一点.

Answer 1

我相信这可以使用如下的分区和排名函数来完成：

SELECT ParentGroup_Name, ChildGroup_name, [Entity_name], 
    999 + DENSE_RANK() OVER(PARTITION BY ParentGroup_Name ORDER BY ChildGroup_name) AS [ChildGroupSequence], 
    99 + ROW_NUMBER() OVER(PARTITION BY ParentGroup_Name, ChildGroup_name ORDER BY ChildGroup_name, Entity_name) AS [EntitySequence]
FROM @ChildGroupEntity cge
INNER JOIN @ChildGroup cg ON cg.ChildGroup_id=cge.ChildGroup_id
INNER JOIN @parentGroup pg ON pg.parentGroup_id=cg.parentGroup_id
INNER JOIN @entity e ON e.[entity_id]=cge.[Entity_ID]
ORDER BY ParentGroup_Name, ChildGroup_name, [Entity_name]

此查询生成您所描述的示例输出。您的示例数据似乎没有正确反映第一个规则，但该规则规定 ChildGroupSequence 应增加 100 并且示例输出增加 1。第二个查询反映了增量 100：

SELECT ParentGroup_Name, ChildGroup_name, [Entity_name], 
    900 + 100 * DENSE_RANK() OVER(PARTITION BY ParentGroup_Name ORDER BY ChildGroup_name) AS [ChildGroupSequence], 
    99 + ROW_NUMBER() OVER(PARTITION BY ParentGroup_Name, ChildGroup_name ORDER BY ChildGroup_name, Entity_name) AS [EntitySequence]
FROM @ChildGroupEntity cge
INNER JOIN @ChildGroup cg ON cg.ChildGroup_id=cge.ChildGroup_id
INNER JOIN @parentGroup pg ON pg.parentGroup_id=cg.parentGroup_id
INNER JOIN @entity e ON e.[entity_id]=cge.[Entity_ID]
ORDER BY ParentGroup_Name, ChildGroup_name, [Entity_name]

请参阅此示例 SQL Fiddle以获取这两个查询的示例。

也许查询应该按 ID 而不是名称分区，如果是这样，苏塞克斯将排在埃塞克斯之前，因为它的 ID 较低，查询将是这样的：

SELECT ParentGroup_Name, ChildGroup_name, [Entity_name], 
    900 + 100 * DENSE_RANK() OVER(PARTITION BY pg.ParentGroup_ID ORDER BY cg.ChildGroup_ID) AS [ChildGroupSequence], 
    99 + ROW_NUMBER() OVER(PARTITION BY pg.ParentGroup_ID, cg.ChildGroup_ID ORDER BY cg.ChildGroup_ID, cge.Entity_ID) AS [EntitySequence]
FROM @ChildGroupEntity cge
INNER JOIN @ChildGroup cg ON cg.ChildGroup_id=cge.ChildGroup_id
INNER JOIN @parentGroup pg ON pg.parentGroup_id=cg.parentGroup_id
INNER JOIN @entity e ON e.[entity_id]=cge.[Entity_ID]
ORDER BY pg.ParentGroup_ID, cg.ChildGroup_ID, [Entity_name]